Function Nrecv

src/net.c:414–505

/********************************************************************/

int
Nrecv(int fd, char *buf, size_t count, int prot, int sock_opt)
{
    register ssize_t r;
    register size_t nleft = count;
    struct iperf_time ftimeout = { 0, 0 };

    fd_set rfdset;
    struct timeval timeout = { nread_read_timeout, 0 };

    /*
     * fd might not be ready for reading on entry. Check for this
     * (with timeout) first.
     *
     * This check could go inside the while() loop below, except we're
     * currently considering whether it might make sense to support a
     * codepath that bypasses this check, for situations where we
     * already know that fd has data on it (for example if we'd gotten
     * to here as the result of a select() call.
     */
    {
        FD_ZERO(&rfdset);
        FD_SET(fd, &rfdset);
        r = select(fd + 1, &rfdset, NULL, NULL, &timeout);
        if (r < 0) {
            return NET_HARDERROR;
        }
        if (r == 0) {
            return 0;
        }
    }

    while (nleft > 0) {
        if (sock_opt)
            r = recv(fd, buf, nleft, sock_opt);
        else
            r = read(fd, buf, nleft);

        if (r < 0) {
            /* XXX EWOULDBLOCK can't happen without non-blocking sockets */
            if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
                break;
            else
                return NET_HARDERROR;
        } else if (r == 0)
            break;

	if (sock_opt & MSG_TRUNC) {
            size_t bytes_copied = (r > nleft)? nleft: r;
            nleft -= bytes_copied;
            buf += bytes_copied;
        }
	else {
            nleft -= r;
            buf += r;
        }

        /*